D1-Septage-Management-Practices-World

7/28/2019 D1-Septage-Management-Practices-World

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Septage ManagementPractices and BMGF projects

Action Planning Workshop for Improving Sanitation Conditions inKhulna

Khulna, Bangladesh

1-2 July 2013

Prof. Dr. Zifu Li

Centre for Sustainable Environmental Sanitation (CSES)

University of Science and Technology Beijing

北京科技大学 University of Science & Technology Beijing

The views expressed in this paper/presentation are the views of the author and do not necessarily reflect the views or policies of the AsianDevelopment Bank (ADB), or its Board of Governors, or the governments they represent. ADB does not guarantee the accuracy of the data

included in this paper/presentation and accepts no responsibility for any consequence of their use. Terminology used may not necessarily be

consistent with ADB official terms.




Introduction

Part 1: The state of the art in septage management

Part 2: Fecal sludge management technologies inChina

Part 3: Case studies – Fecal sludge management

projects by anaerobic biogas digestion in

Dakar/Senegal and Ouagadougou/Burkina Faso




Part 1: The state of the art in Septage Management 1. Definition of Septage The partially treated waste store in a septic tank is called Septage.

It generally consists of all the household wastes that are disposed

of through a home's plumbing system that neither drain out into

the soil nor are converted to gases by the bacteria in the tank.

Septage is generally split into three parts in a septic

tank:Scum, which floats to the top and is generally where the bacteria

live that treat the waste;

Effluent , which is the semi-treated liquid that comprises the

majority of the material in the septic tank;

Sludge, the solids which collect at the bottom of the tank




Part 1: The state of the art in Septage Management

High-income

residential

Low-density

development with

large plots and

ample

open space.

Most properties have

septic tanks with or

without a soakaway. Septic tanks are often poorly

maintained, and partially treated

wastewater is discharged into

open drains, creating a public

health risk. In some cases there

are sewer

connections. Demand for water for irrigation

of gardens.

Medium-income

residential

Medium-sized plots

with some space

around houses. Cistern flush and pour

flush toilets

connected to septictanks or leach pits.

As above: on-site sanitation is

often poorly operated and

maintained. Partially treatedwastewater is discharged into

open drains, creating a

public health risk. Sewers are laid in

some areas but

system is only partial.

Current Typical Sanitation Services for Different Residential Settlement TypesSource: Technology Options for Urban Sanitation in India




Low-income

residential

(formal

development)

Medium-density housing with

small plots developed

according to planning norms (road

width, plot sizes, and so on).

Pour flush toilets connected to

leach pits or septic tanks,

the latter discharging into open

drains or sometimes sewers. As above.

Multistorey

residentialapartments

High-density, medium-low

income. Either connected to sewerage or

have shared septic tanks. Malfunction of septic

tanks and soak pits.

Low-incomeinformal

settlements

Unplanned development with

medium- to high-density housing

and small plots. Some households have no private

facility. Septic tanks and

leach pits are poorly

maintained. Many plots subdivided and/or

houses converted tomulti-storey.

Existing leach pits and septic

tanks discharging directlyinto street drains.

Community toilets

are often poorlymaintained and

unhygienic. Residents may lack tenure. Community or public

toilets may be available. Ponding of

wastewater on

surfaces. Inadequate drainage and water

supply.

Current Typical Sanitation Services for Different Residential Settlement Types




Illegalsquatter

slum

settlements

(jhughi-jhopri

clusters)

High-density, verylow-income population,

lack of tenure,

precarious housing. Some householdshave their own

toilet. Need to eradicate

open defecation.

Narrow access laneswith poor services.

Many use shared

or communaltoilets, or practice

open defecation. May be insufficient

space to build householdtoilets for all.

Quality of construction

and servicing of

facilities is very poor. Lack of land tenure

may constrain spending on

improvements. Existing toilets may

discharge into street

drains (nalas), creating a

public health risk.





Resettlement

colony

Medium-high

population density. In some cases,

development is planned

and houses

are constructed with

toilets and leach pits.

Poor maintenance,

inadequate services

for fecal sludge collection and

treatment. Basic infrastructure

and some level of

access to municipal

services. In others, many houses lack

a toilet. Open defecation may be

common. Community toilets

with septic tanks may

be available. Poor maintenance of community toilets.

Urban village,

former ruralvillage

overtaken

by urban

spread

Medium-high

density,

mixed income.

Coverage variable; existing

toilets mostly have septic

tanks or leach pits

discharging into opendrains or canals.

Poor maintenance of

toilets, inadequate services for

fecal sludge collectionand treatment. Open defecation may be

common. Possible demand for

wastewater from farmers.





Institutional

buildings

(academic

campuses, army

cantonment,

hospitals) and

hotels

Large areas of open

space surrounding

large buildings. Large septic tanks

with soakaways. Poor maintenance.

Unregulated septage

removal and

inadequate

treatment.






Figure 7: suitable treatment processes for developing countries comprise

Source: Doulaye Koné and Martin Strauss.

Solids-liquid separation:

Settling/thickening tanksor ponds (non-mechanised,

batch-operated)

Unplanted drying beds

Constructed wetlands

Pond treatment of FS

supernatants or percolatesCombined composting (“co-

composting”) with organic solid

waste

Anaerobic digestion with biogasutilization

Suggested processes for fecal sludge treatment




Part 1: The state of the art in Septage Management Process Technology Mode of operation Residual or

end products

Physical process Screening

Removal of large particles

by coarse screening Sludge

Sedimentation Settlement of suspendedsolids by gravity

Sludge

Biochemical

process

Aerobic degradation Breakdown of organic

matter by bacterial

activity in the presence of

oxygen

Carbon

dioxide,water and

sludge (microbial

biomass)

Anaerobic digestion As above but bacterial

action in the absence of

oxygen Methane, carbon

dioxide and sludge

(microbial biomass)





Figure 7: Schematic summarising main options for FSM.

Source: Guy Norman (WSUP) & Jonathan Parkinson (IWA), etc. 2011.





Figure 7: Appropriate FS treatment options in developing countries .

Source: Martin Strauss.




Part 2. Fecal sludge management technologies in China




Part 2: Fecal sludge management technologies

Urban feces route in China

Urban Feces

(private

households,

public buildings,

public toilets,

feces tanks)城市粪便

Sewers下水道 WWTP污水厂

Runoff Drainages

雨水径流排水

Water Body (water

pollution) 水体

Transportation输送系统

Sewer

下水道

WWTP

污水厂

Agricultural Fertilizer农肥

Urban Feces Disposal

Plant城市粪便处理厂




1. Collection 收集系统

1.1. Vaults and chambers收集室





1.2. night soil storage tank system粪便储存池





1.3. septic tank and sewer system化粪池和排水管道




2. Transportation 输送设备

http://images03.edeng.cn/uimages/1/33/70/%E4%BE%9B%E5%BA%94%E4%B8%89%E8%BD%AE%E5%90%B8%E7%B2%AA%E8%BD%A6%E5%B0%8F%E5%9E%8B%E6%B2%BC%E6%B6%B2%E8%BD%A6-6192216_b.gif

http://img.diytrade.com/cdimg/1056029/11402152/0/1260523481/Suction_night_soil_collection_vehicle.jpg




3. Treatment处理工艺

Composted

PretreatmentSolid-liquid

separation

Wastewater

biological treatment

Landfill

Thickening andanaerobic digestion

Figure 2-6. Flow chart of complete hygienic treatment





Figure 2-7. Flow chart of co-treatment with municipal waste

water treatment plant

Landfill


separation

Transferred to

WWTP

Compresseddewatered




Figure 2-8. Flow chart of co-treatment with municipal rubbish

landfill plant

Landfill


separation

Landfill leachate

WWTP

Compressed

dewatered





Figure 2-9. Flow chart of co-composting with domestic waste

Pretreatment

Mix with domestic

waste Co-compost

PretreatmentMix with agriculture

waste Co-compost

Figure 2-10. Flow chart of co-composting with agriculture waste





Figure 2-11. Flow chart of storage tanks model

Figure 2-12. Flow chart of biogas digesting model

Pretreatment Storage tank WWTP

Sludge treatment

Pretreatment Digesting WWTP

Sludge treatment


Fecal sludge management technologies inChinaFecal sludge management technologies inChina




3. Household-based Small scale (decentralized facilities)

biogas plant development in China

a) Fixed Dome b) Floating Dome Figure 1-1: Schematic of two kinds of small scale biogas reactors




Small Scale Biogas System models

“Three in One” eco-agricultural model“三位一体”模式





“Four in One” eco-agricultural model “四位一体”模式





“Five in One” eco-agricultural model “五位一体”模式




Multi-Household Based or Community Based Biogas Plantfrom modified large scale plants联户沼气池类型

CSTR Biogas storageintegrated CSTR

UASB




Multi-Household Based or Community Based Biogas Plant

1. biogas production 2 biogas

storage

3. biogas distribution

Main components of multi-household biogas plant system

联户沼气系统主要组成部分




Hybrid anaerobic reactor system (DEWATS system)

组合式厌氧系统




Part 3: Case studies –

Fecal sludge managementprojects by anaerobic biogas digestion in

Dakar/Senegal and Ouagadougou/Burkina Faso

北京科技大学




Background of the projects

The objective of the Water, Sanitation and Hygiene team of theBill and Melinda Gates Foundation:

盖茨基金会水和卫生团队的工作目标：

“to develop and introduce in developing country urban conditions

a system to safely process human waste” 在发展中国家研发和实施安全的粪便处理系统

probably together with urban organic household waste - and

possibly waste from peri-urban agriculture - into products that can

be re-used and generate revenue.粪便污泥与有机垃圾混合处理，产品能够产生价值

Areas of interest: primarily Africa and South Asia.

主要应用区域：非洲和南亚

北京科技大学




One of the options the Foundation wishes to explore furtherif biogas (anaerobic digestion) technology developed in

China can be used to process faecal sludge safely and cost-

effectively

利用中国沼气技术安全和经济有效地处理粪便污泥

to process a range of waste streams, including fecal sludge,

at a scale ranging from 2-10 tons of waste/day (for

decentralized facilities) up to a potential maximum of several

hundred tons/day (for centralized facilities).

处理粪便污泥范围从2-10吨/日（分散处理）到最大数百吨/日（集中处理）


北京科技大学




To work with, and fund a partner or consortium of

partners in China to develop and test biogas sanitation

plants, or series of decentralized plants, in one of the

Gates foundation partner cities in Africa (which have tobe determined) to process fecal sludge with other

organic urban waste streams.

与中国的一个合作伙伴或联合体合作，资助研发和

试验沼气卫生设施或者多个分散处理设施，并将在基金会在非洲的某一个合作伙伴城市进行粪便污泥与有机垃圾混合处理的研发和示范


北京科技大学




Dakar

北京科技大学




北京科技大学




3 sites / 7 options

北京科技大学




38

Burkina Faso

Ouagadougou (Capital City)

北京科技大学




1 site / 4 options

北京科技大学




Conclusions

FSM is a crucial issue for water, sanitation and

hygiene

Anaerobic digestion system may be a good

alternative solution with multiple benefits in urbancontext of developing countries

Successful demon-project is a key for promoting such

technology in developing countries




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D1-Septage-Management-Practices-World